1. Technical Field
The present invention relates to a recording apparatus and a liquid ejecting apparatus. In particular, the present invention relates to a recording apparatus and a liquid ejecting apparatus using ultraviolet curing type ink.
2. Related Art
There is a recording apparatus or a liquid ejecting apparatus for forming an image or a pattern on a recording medium by using ultraviolet curing type ink. The ultraviolet curing type ink has the property in which it takes a long time to be cured till ultraviolet is emitted and the property in which curing is immediately completed when ultraviolet is emitted, which are preferable for print ink. In addition, the ultraviolet curing type ink has an advantage in that it imposes a small environmental burden as no solvent is vaporized in the process of curing.
Further, the ultraviolet curing type ink has excellent properties. For example, the ultraviolet curing type ink shows high adherence property to a various recording mediums due to the composition of vehicle, is scientifically stable after curing, has high adhesiveness, drug tolerability, weather resistance, abrasion resistance, and the like, and can be withstood to outdoor condition. Consequently, an image can be formed not only on a thin sheet-like recording medium such as a paper, a resin film, a metallic foil, and the like but also on a label surface of an optical recording medium, a textile product, and the like having a three dimensional surface shape to some extent.
As for the method for adhering ultraviolet curing type ink on a recording medium, application, printing, and the like are exemplified. However, it is expected that ultraviolet curing type ink is utilized for an ink jet type recording apparatus in which any image or patter can be formed with high accuracy without a lithographic plate. In the ink jet type recording apparatus, an image can be recorded on any area also to a long recording medium or a recording medium having a large area by using a nozzle whose size is limited by the combination of reciprocating movement of a recording head for ejecting ink and movement of a recording medium in the direction perpendicular to the direction of the reciprocating movement of the recording head.
In JP-A-2004-155046, an ink jet recording apparatus is described. In the ink jet recording apparatus, an ultraviolet curing agent is included in ink and ultraviolet is emitted on a recording surface right after recording, thereby improving quick-drying of recording surface. To be more specific, it is described that ultraviolet curing type ink is used as ink and the ink adhered on a recording medium is immediately cured to fix thereon by ultraviolet lumps disposed at the both ends of a recording head in the main scanning direction in an ink jet printer.
Further, in JP-A-2005-324443 and JP-A-2005-125513, there is described an image forming apparatus having a recording head for ejecting ink that is cured by ultraviolet emission and an ultraviolet emission unit coupled to the recording head and in which an image support body, the recording head, and the ultraviolet emission unit are relatively moved. In the image forming apparatus described in the patent documents, an input digital image is formed by scanning of a plurality of recording head on the record support body and ink is independently cured by ultraviolet emission for every scan. Further, in JP-A-2004-042548, it is described that an ultraviolet emission device is independently provided for every color in the recording apparatus that ejects ultraviolet curing type ink having a different color to each other from nozzles to perform color printing.
The ultraviolet curing type ink has different transmittance property to ultraviolet depending on the type, for example the color, of the ink, so that curing speed is also different. Further, the transmittance property to ultraviolet is also changed in accordance with the thickness of ultraviolet curing type ink adhered on a recording medium. Consequently, when recording operation is performed by using different type of inks for color printing or the like, there is a case in that curing of a specific type of ink takes a long time. However, when the ink which is not yet cured is mixed on the surface of a recording medium, bleeding occurs in an image after curing, thereby deteriorating image quality.
Further, when ultraviolet is emitted for the ink which is most difficult to cure, there is a case that not only emission energy is uselessly consumed, but also curing speed of another type of ink becomes too fast. The ultraviolet curing type ink itself is cured and fixed, so that the volume of the ink does not decrease after adhesion. Consequently, when the curing speed is too fast, the ink is cured to rise from the surface of a recording medium and the surface texture becomes coarse.
It is proposed that the mutual difference of the property of the type of the ultraviolet curing type ink is compensated by, for example, adjusting the composition of the ultraviolet curing component contained in the ink. However, the difference is not compensated. Further, it is proposed that an ultraviolet emission device is independently provided in accordance with the ink ejected from each of recording heads. However, there occurs problems in that the weight and the size of the carriage becomes too large, the scale of the device becomes large, and the improvement of operational speed is restricted in the structure in which a recording head and a plurality of ultraviolet emission devices are mounted on a plurality of carriages.